Preparing to revert
If you used Version 12.10, you must prepare your system for reversion to the pre-migration version of the database server.
Review and complete all tasks that apply:
- Review the database schema prior to reversion.
- Check and configure available space for reversion.
- Save copies of the current configuration files.
- Save system catalog information.
- Verify the integrity of the Version 12.10 data.
- Back up Informix Version 12.10.
- Export or save your data.
- To prevent reversion issues:
- Resolve outstanding in-place alter operations.
- If you have empty tables with no extents, drop those tables.
- Defragment partitions by using the SQL administration API.
- Remove unsupported features.
- Remove new BladeManager extensions.
If you use high-availability clusters or Enterprise Replication, you must complete extra tasks before you can revert to the pre-migration version of Informix.
- Review the database schema prior to reversion
You must review your database schema to determine if reversion is possible. You can revert from Informix Version 12.10 to the database server from which you migrated, if you have not added any extensions to the Version 12.10 database server and you are not reverting from a newly created instance. - Reversion requirements and limitations
If you used the new database server, you must review a list of reversion requirements and limitations, and then complete any prerequisite tasks before you revert. If the reversion restrictions indicate that you must drop objects from the database, you can unload your data and then reload it in the prior database server. - Check and configure available space for reversion
You must be sure you have enough space for reversion to the source database server. - Save copies of the current configuration files
Save copies of the ONCONFIG and concsm.cfg files for when you migrate to Informix Version 12.10 again. - Save system catalog information
If your current database server instance uses secure-auditing masks or external spaces, and you want to preserve the associated catalog information, you must unload these system catalog tables before you revert. - Verify the integrity of the Version 12.10 data
Verify the integrity of your Version 12.10 data, if you did not do this after you migrated. - Back up Informix Version 12.10
Before you begin the reversion, make a complete level-0 backup of Informix Version 12.10. - Resolve outstanding in-place alter operations
You must resolve outstanding in-place alter operation before you revert to a previous version of the database server. An in-place alter is outstanding when data pages still exist with the prior definition. - Remove unsupported features
Before you revert, remove all features that your older database server does not support. - Remove new BladeManager extensions
When BladeManager or SQL Registration are used to register an extension in a database, the ifxmngr Client SDK module, which manages extensions, is registered first. If you need to revert from Version 12.10, and you ran BladeManager against a database, you must remove all BladeManager extensions.
Parent topic: Reverting from Informix Version 12.10
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